Arrangement in loader buckets and the like provided with digging blades

ABSTRACT

An arrangement for a loader bucket provided with digging teeth which are reciprocably displaceable in their longitudinal direction to create a picking action of the teeth against the surface to be broken and penetrated. The apparatus includes a leaf-spring arrangement which is in engagement with and actuated by a drive mechanism so as to create an oscillating movement of the teeth in the direction of swing. One end of the spring is connected to hammer means adapted to actuate, by means of impact, one or more digging teeth in a direction of movement away from the loader bucket.

United States Patent Sonerud 1 1 Feb. 29, 1972 [54] ARRANGEMENT IN LOADER BUCKETS AND THE LIKE PROVIDED WITH DIGGING BLADES [72] Inventor: John Teodor Sonerud, Hudiksvall, Sweden [73] Assignee: Svenska llymas Aktleholag, l-ludiksvall,

Sweden 221 Filed: Sept. 30, 1968 21 Appl.No.: 763,850

[30] Foreign Application Priority Data Sept. 28, 1967 Sweden ..l3364/67 May 17, 1968 Sweden ..6748/68 [52] US. Cl ..37/l41, 173/119, 299/67, 37/142 [51] Int. Cl. ..E02f 9/28 [58] Field of Search ..'......37/141, 142; 299/67, 94; 173/119, 120

[56] References Cited UNITED STATES PATENTS 1,067,375 7/1913 Proctor ..37/l4l X 1,945,322 1/1934 Lafayette... .....299/94 X 2,228,445 1/1941 De Velbiss. ..299/67 3,269,039 8/1966 Bodinem, .....37/l4l X 3,293,778 12/1966 McAuliff ..37/l4l 3,478,450 11/1969 Cunningham ..37/141 Primary Examiner--Edgar S. Burr Attorney-Woodhams, Blanchard and Flynn [57] ABSTRACT An arrangement for a loader bucket provided with digging teeth which are reciprocably displaceable in their longitudinal direction to create a picking action of the teeth against the surface to be broken and penetrated. The apparatus includes a leaf-spring arrangement which is in engagement with and actuated by a drive mechanism so as to create an oscillating movement of the teeth in the direction of swing. One end of the spring is connected to hammer means adapted to actuate, by means of impact, one or more digging teeth in a direction of movement'away from the loader bucket.

10 Claims, 3 Drawing Figures Patented Feb. 29, 1972 B Sheets-Sheet l Z My 0 T w V w z/ Patented Feb. 29, 1972 2 Sheets-Sheet 2 ARRANGEMENT IN LOADER BUCKETS AND THE LIKE PROVIDED WITH DIGGING BLADES It is previously known to provide material moving shells, such as loader buckets, with oscillating or vibrating digging teeth or breakers, to cause the teeth to pick or hack at the ground in conjunction with the digging movement. The majority of apparatus designed to effect digging operations in this manner, require that a considerable amount of power is delivered to the means arranged to actuate the breakers to perform the aforesaid picking action.

The present invention is concerned with an arrangement in which only a relatively small driving force is required to provide a relatively powerful picking action of one of the teeth or breakers of the bucket, and is mainly characterized in that said arrangement includes a set of leaf springs, the one end of which is connected with a drive mechanism for creating an oscillatory movement in the swinging direction of the end of the spring unit, while the other end of said set of springs is connected to a hammer means, adapted to actuate impactwise one or more bucket teeth in a direction of movement away from the loader bucket.

The invention will now be described with reference to the accompanying drawing, in which 7 FIG. 1 shows an arrangement according to the invention adapted to a loader bucket seen from the'side and in section,

FIG. 2 is a plan view, partly in section, of the arrangement in FIG. 1, and

FIG. 3 shows in side view another embodiment of the arrangement illustrated in FIG. I.

The illustrative embodiment of FIG. 1 comprises a loader bucket, generally indicated by the reference numeral 1, and presenting a bucket cavity 2, teeth or breakers 3 and a closed space 4, defined by the outer walls 5 of the bucket and the inner wall 6 of the bucket space 2. Attached to a portion of one outer wall 5 are attachment flanges 7, to facilitate attachment of the loader bucket to a jib or the like. Mounted at the inside of the inner wall 6 within the closed space 4 are two identical groups of leaf springs 8, each of which is anchored in the center thereof to said inner wall through the intermediary of a spring support frame 9. The frame 9 supports centrally arranged transversely extending pins 10 and 11, each of which projects out on its respective side of the support frame, perpendicular to the longitudinal direction of the respective spring units. The pins support ball bearings 12,13 for mounting respective pivot arms 14,15, each of which branches into two legs 14',l4" and 15',15" respectively, the ends of which An alternative embodiment for imparting a picking or hacking movement to the teeth or breakers of a loader bucket whilst, for instance, the bucket digs into the ground, is shown in FIG. 3. This embodiment comprises a loader bucket 32 which is pivotally supported on a jib or arm 33. The digging movements of the bucket are obtained with the assistance of a hydraulic cylinder 34, located between the jib 33 and the front portion of the bucket. The bucket is provided with teeth or breakers 35, arranged on the end of a piston rod 36 which carries a piston 37 at its upper end is capable of sliding between two wall portions, an inner portion 38 and-an outer portion 39.

are connected with and support a hammer device 16, provided in the middle with a slot 17 through which one end 18 of the leaf spring units is fitted. The hammer device 16 is adapted to cooperate with the inner end surface 19 of the appropriate bucket tooth, each of the teeth being movable backwards and forwards in its longitudinal direction between two limits defined by a pin-and-slot-connection indicated generally at 20. The spring support frame 9 is also provided with bearing means 21,22 for two lever arms 23,24 respectively, which extend parallel with respective sets of springs and are rigidly connected to a bracket 25 at the other end 26 of the respective spring unit 8. The bracket 25 includes a pivot pin 27, by

which it is pivotally connected to a connecting rod 28, the other end of which is connected with a stud 29 mounted'on ashaft 30 which is journaled for rotation in a bearingframe 31. I

The shaft 30 is driven by a chain 32 of a hydraulic motor '33.

springs 8, which results in that the last mentioned ends of the 1 sets of springs will swing, and carry the hammer means 16 and also the pivot arms 14,15 in an oscillating, swing movement,

whereup the hammer means 16 will actuate the end surfaces 19 of the bucket teeth or breakers 3.

The wall portion 39 forms the front, outer restricting wall of the loader bucket and merges into an upper portion 40 which forms the upper outer wall of the bucket. The wall portion 38 merges into a wall portion 41 which extends parallel to the wall portion 40, wherewith the wall portions 38 and 41 from two of the inner defining surfaces of the bucket. The wall portions 40 and 41 are connected at their outer ends with a short wall 42. The lower ends of the wall portions 38 and 39 are provided with guides 43 and 44, respectively, for slidably guiding the inner portions of the teeth or breakers 35. Arranged on the piston rod 35 between the piston 37 and the guides 43, 44 is a coil spring 45. Disposed in the same slide path as the piston 37 is a hammer means 46, adapted to actuate the upper surface of piston 37, and thus the teeth or breakers 35, impactwise. The piston 46 is connected by means of a linking member 47 to a strong leaf spring 48, which in practice comprises a set of springs as in the previously described embodiment. The other end of the spring or set of springs 48 is fixed to a fixed bracket 49 attached'to the short wall 42. The spring 48 is adapted to be urged by a stationary abutment 50 against the surface of a rotatable eccentric 51 which is mounted on a drive shaft 52, which in turn is connected to some suitable power source.

In order to better explain the correct functioning of the arrangement according to the invention a more detailed analysis will now be given of the conditions necessary for the arrangement to work in the desired manner, so that the greatest possible impact efiect is obtained with a relatively small force applied to the impacting device, and a smoother functioning of the driving mechanism.

It can be stated quite generally, that in order to pick and back hard ground a heavy hammer is required which must be given a high-impact rate. Consequently, the drive means must supply energy to the hammer to cause it to accelerate and to spring to one side as impact occurs, to prevent the drive mechanism from being damaged by the high-impact forces. This problem is solved by means of the arrangement-described above, by causing the hammer to be operated by an eccentric or crank arrangement, via a spring.

Since the hammer means is suspended by an essentially linear spring the spring-mass of the system has a natural frequency. If the arrangement is operated undisturbed at the critical speed of the drive mechanism the amplitude of the hammer means becomes'unlimited, and the spring may finally break. In tests carried out in practice and drive mechanism has been driven at a speed of S00 revolutions per minute. Calculations show that the greatest impact forces are obtained when operating just above the critical speed. If the number of revolutions is increased above this speed the amplitude decreases, and at a speed of l,000 revolutions per minute the hammer means is practically stationarya Consequently, either hydraulic or pneumatic stop means must be provided to inhibit movement of the hammer means when the teeth of the bucket are no longer in contact with the ground, e.g., when A I A 4: Nu-

c. The spring should be sufficiently stiff to lift the hammer at the right moment, i.e., upon completion of a hammering stroke.

A spring device of the aforementioned type is linear, and hence must be adapted to a mean value of all three conditions. Furthermore, with regard to the desired condition of natural oscillation it has a relatively limited range of speed in which good functioning can be obtained. Practical tests and experiments with the embodiment of FIGS. 1 and 2 have shown that with a spring unit of total length 885 mm. and a length of 412.5 mm. between the engagement point of the hammer means with the center of the spring unit, a largest thickness of I12 mm. a speed of 700 revolutions per minute has been reached as the idealistic speed, with a crank radius of the crank stub 29 of 35 mm., a length of 155 mm. on the connecting rod 29, a hammer means weighing 12.6 kg. and a breaker of 86 kg. Thus, an operating condition is obtained at said number of revolutions at which a great impact force is delivered to the breaker 3 and in which the hammer does not reach the aforementioned amplitude when the bucket is lifted, i.e., when the breakers are no longer in contact with the ground and is in its most outwardly projected position. In this arrangement the number of revolutions should be maintained in practice at 700 or somewhat more. This avoids the use of extra means for restricting the amplitude; these means are expensive, since they must be capable of absorbing energy with regard to the large impact forces which occur.

As will be understood, the present invention provides an arrangement in loader buckets which, with regard to method of operation and construction, are muchsuperior to hitherto known loader bucket arrangements provided with vibratory, picking teeth.

The arrangement is also relatively inexpensive to install, and requires but small space in the bucket.

The arrangement can also be modified within the scope of the following claims. Thus, one end of the spring can be actuated by a reciprocating piston-cylinder-arrangement instead of the shown eccentric or crank connecting rod mechanism. Furthermore, in the embodiment of FIG. 1 it is not necessary to provide the arrangement with the pivot arms 14,15 and lever arms 23,24, although these are to be preferred in practice, but the crank connecting rod mechanism can be adapted to actuate the end 26 of the spring unit 8 through some suitable fitting and the hammer means 16 can be attached direct to end 18 of the said spring. it is also conceivable to journal the spring unit 8 in the frame member 9, to provide a doublearmed lever. The bucket cavity 2 and 32 shown in the drawings can, of course, be made larger or smaller according to requirements.

lclaim:

1. An arrangement in excavating machines having a material moving shell provided with digging teeth which are reciprocatingly displaceable in their longitudinal direction to create picking or hacking action of the teeth against the surface to be broken and penetrated, comprising in combination: a drive mechanism, a leaf-spring having a first portion secured at a fixed location on the shell and having a second portion which is in engagement with and actuated by said drive mechanism so as to flex said spring and thereby create an oscillating movement of one end of said spring remote from said first and second portions, and hammer means, said one end of the spring engaging the hammer means, the hammer means being adapted to actuate impactwise one or more of the digging teeth in a direction of movement away from the shell.

2. An arrangement according to claim 1, wherein the hammer means is attached to the ends of pivot arms pivotally mounted on the shell at the location at which the leaf spring is secured to the shell, wherein the direction of swing of the pivot arms is parallel to the direction of swing of the spring.

3. An arrangement according to claim 2, wherein each pivot arm comprises two leg members, at the ends of which is connected the hammer means.

4. An arrangement according to claim 1, wherein the center portion of the leaf spring is attached to a spring support frame on the shell, which rame 18 provided with bearing means for lever arms which are connected with the other end of the leaf spring by means of a bracket fitting'which is in connection with the drive mechanism.

5. An arrangement according to claim 4, wherein the drive mechanism comprises a crank mechanism, the connecting rod of which is connected with said bracket fitting and adapted to be drive by a suitable motor.

6. An arrangement according to claim 1, wherein the drive mechanism comprises a rotatable eccentric against which the spring is held in abutment by means of an abutment member fixed to said shell.

7. An arrangement according to claim 6, wherein that the end of the spring remote from the hammer means is attached to a fixed bracket, and that said spring is passed between the eccentric and the abutment member into engagement with the hammer means.

8. An arrangement according to claim 1, wherein the leaf spring is pivotally mounted at its center point.

9. An arrangement according to claim 1, wherein the teeth are reciprocatingly movable in their longitudinal direction between two limit positions which are defined by a pin-andgroove-connection.

10. An arrangement in a material moving shell for excavating machines provided with digging teeth which are reciprocatingly displaceable in their longitudinal direction with respect to the shell to create picking and hacking action of the teeth against the surface to be broken and penetrated and having a leaf spring means which is in engagement with and actuated by a drive mechanism to create an oscillating movement in the direction of swing of the ends of the leaf spring means, comprising the improvement wherein one end of said leaf spring means is connected to a hammer means adapted to actuate impactwise one or more digging teeth in a direction of movement away from the shell and the other end of said leaf spring means is connected to the drive mechanism, mounting means connected to said spring means at a point disposed between the ends thereof for attaching said spring means to said shell, a lever member pivotally connected between said drive mechanism and said mounting means, one end of said lever member being pivotally connected to said mounting means substantially adjacent said point of attachment, the other end of said lever member being pivotally connected to said drive mechanism, and said other end of said leaf spring means being disposed in engagement with said lever member adjacent said other end thereof whereby oscillation of said lever member by said drive mechanism causes a corresponding oscillation of said other end of said spring means, which oscillation is transmitted through said leaf spring means to said one end thereof for causing said hammer means to be impacted against said teeth. 

1. An arrangement in excavating machines having a material moving shell provided with digging teeth which are reciprocatingly displaceable in their longitudinal direction to create picking or hacking action of the teeth against the surface to be broken and penetrated, comprising in combination: a drive mechanism, a leaf-spring having a first portion secured at a fixed location on the shell and having a second portion which is in engagement with and actuated by said drive mechanism so as to flex said spring and thereby create an oscillating movement of one end of said spring remote from said first and second portions, and hammer means, said one end of the spring engaging the hammer means, the hammer means being adapted to actuate impactwise one or more of the digging teeth in a direction of movement away from the shell.
 2. An arrangement according to claim 1, wherein the hammer means is attached to the ends of pivot arms pivotally mounted on the shell at the location at which the leaf spring is secured to the shell, wherein the direction of swing of the pivot arms is parallel to the direction of swing of the spring.
 3. An arrangement according to claim 2, wherein each pivot arm comprises two leg members, at the ends of which is connected the hammer means.
 4. An arrangement according to claim 1, wherein the center portion of the leaf spring is attached to a spring support frame on the shell, which frame is provided with bearing means for lever arms which are connected with the other end of the leaf spring by means of a bracket fitting which is in connection with the drive mechanism.
 5. An arrangement according to claim 4, wherein the drive mechanism comprises a crank mechanism, the connecting rod of which is connected with said bracket fitting and adapted to be drive by a suitable motor.
 6. An arrangement according to claim 1, wherein the drive mechanism comprises a rotatable eccentric against which the spring is held in abutment by means of an abutment member fixed to said shell.
 7. An arrangement according to claim 6, wherein that the end of the spring remote from the hammer means is attached to a fixed bracket, and that said spring is passed between the eccentric and the abutment member into engagement with the hammer means.
 8. An arrangement according to claim 1, wherein the leaf spring is pivotally mounted at its center point.
 9. An arrangement according to claim 1, wherein the teeth are reciprocatingly movable in their longitudinal direction between two limit positions which are defined by a pin-and-groove-connection.
 10. An arrangement in a material moving shell for excavating machines provided with digging teeth which are reciprocatingly displaceable in their longitudinal direction with respect to the shell to create picking and hacking action of the teeth against the surface to be broken and penetrated and having a leaf spring means which is in engagement with and actuated by a drive mechanism to create an oscillating movement in the direction of swing of the ends of the leaf spring means, comprising the improvement wherein one end of said leaf spring means is connected to a hammer means adapted to actuate impactwise one or more digging teeth in a direction of movement away from the shell and the other end of said leaf spring means is connected to the drive mechanism, mounting meAns connected to said spring means at a point disposed between the ends thereof for attaching said spring means to said shell, a lever member pivotally connected between said drive mechanism and said mounting means, one end of said lever member being pivotally connected to said mounting means substantially adjacent said point of attachment, the other end of said lever member being pivotally connected to said drive mechanism, and said other end of said leaf spring means being disposed in engagement with said lever member adjacent said other end thereof whereby oscillation of said lever member by said drive mechanism causes a corresponding oscillation of said other end of said spring means, which oscillation is transmitted through said leaf spring means to said one end thereof for causing said hammer means to be impacted against said teeth. 